Ball In Socket Seat Tube Lug

[Scott McLain]

I am curious to see what other's think of the new ball-in-socket seat tube lug that has now found its way on to all Riv bikes.  I don't like it.  I don't know why or why not.  I hate to be critical of our good brothers and sisters at Riv.  I just love the old school lugs.  I would be interested to know how much money is saved going with the ball in socket lug and not using a bottom bracket lug.  Anyone know more about it?

Scott

[Nick Payne]

I like the way that Llewellyn does his socketed seat lugs, but others that I've seen - including the Rivendell ones - leave me cold. About 20 years back I was thinking of buying a Heron frame, but in the end I didn't because it used that design of seat lug.

These is the Llewellyn seat lug (centre):

And how it looks in a finished frame:

Nick

[Ryan M.]

https://rivbike.tumblr.com/post/173252562647/note-this-unearthed-blug-was-supposed-to-appear 

Here is a Blug post that has pictures of the Riv. ball and socket seat tube lug. 

"  The ball-and-socket seat stay joint eliminates sheer forces and adds strength. The main shoreline of the seat lug is familiarly Rivendell, the same-ish swirls and all, and like all Rivendell seat lugs, it has other obsessive details that — well, if you’re going to make it from scratch, might as well be there— "

I have an Appaloosa with the older non-ball and socket lug and just picked up a Frank Jones with the new ball and socket lug and have to say I really dig the new style. It looks nice and has some extra "cream" windows in the lug that the other one doesn't have. I think it is visually appealing and if had to choose between the two I would go with the lug that the Frank Jones has. Not that there is anything wrong with the lug on the Appaloosa, but the Frank is just a bit fancier looking.

[ted]

I think the main advantage of the RBW ball and socket seat lug is that it works for most any seat stay to seat tube angle, so one casting works for all sizes.

Aesthetics are always in the eye of the beholder. Personally I like the looks of the new lug fine. Of course others may not.

Another beneficial feature of the new lug is that the stays will trap the handle end of a frame pump nicely. On my FJ Sr. I put a topeak frame pump along the back side of the seat tube with one end on the left side chain stay and the other tucked between the seat stays at the seat lug. Nice.

[S]

In addition to the advantages Ryan mentions, I suppose another advantage of the ball-and-socket lug is that it allows Grant to use the same lug on different bikes and to tweak the rear end on existing models, all without having to design and pay for a new lug each time.

I don't like the looks of the ball and socket lug either, I think it looks sort of clunky, but developing and casting new lugs is super expensive, and if I am right about the flexibility it affords, then I can't argue with the design on practical grounds.

[ted]

Yep, frame size and design flexibility. One lug to rule them all.

Aesthetically I do prefer the classic seat stay capped and brazed to the side of the seat lug design, but I like the new lug just fine too.